一种点扫描形貌测量系统的现场标定方法

Structure parameters field calibration of fly point scanning shape measurement system

针对三角法点扫描形貌测量系统结构参数标定的非线性问题,提出并实现了一种简单易行的系统结构参数现场标定方法.利用二维靶标在测量空间内自由摆放,根据靶标上特征点及其像点间的位置关系,基于坐标系转换实现了点扫描形貌测量系统结构参数的精确标定.通过对平面及已知直径圆柱面进行测量,利用测量点到拟合平面或圆柱面的距离评价了系统标定的精度.所提标定方法无需精密调整靶标位置,具有较高的可靠性与实用性;也可用于其它基于三角法原理的三维形貌测量系统结构参数的标定.

The calibration of structure parameters of a triangulation-based fly point scanning shape measurement system is usually a non-linear problem.A practical and easy-to-use calibration procedure of such system was proposed and implemented.The proposed calibration procedure was based on the coordinate transformation between the feature points and their images taken by the measurement system.Several pictures of a special designed planar calibration board were taken from arbitrary orientations.There was no need to precisely measure the position and altitude of the calibration board.A planar board surface and a cylinder surface with known diameter were measured by using the obtained structure parameters.The average error of the distances between measuring points and the fitted plane or cylinder was used to evaluate the calibration accuracy.The proposed calibration procedure can meet the needs of the calibration such as validity and stabilization.It can also be used for the calibration of other triangulation based shape measurement systems.